Nitride semiconductor light emitting diode

ABSTRACT

A nitride semiconductor light emitting diode (LED) comprises an n-type nitride semiconductor layer; an electron emitting layer formed on the n-type nitride semiconductor layer, the electron emitting layer being composed of a nitride semiconductor layer including a transition element of group III; an active layer formed on the electron emitting layer; and a p-type nitride semiconductor layer formed on the active layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No.10-2006-0082374 filed with the Korean Intellectual Property Office onAug. 29, 2006, the disclosure of which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a nitride semiconductor light emittingdiode (LED) in which an electron emitting layer having excellentcrystallinity is grown so that light emission efficiency and ESD(electrostatic discharge) characteristic of the LED can be enhanced.

2. Description of the Related Art

Generally, nitride semiconductors are widely used in green or blue lightemitting diodes which are provided as light sources in full-colordisplays, image scanners, various signal systems, and opticalcommunication equipments. Such a nitride semiconductor LED includes anactive layer disposed between n-type and p-type nitride semiconductorlayers, the active layer having a single quantum well (SQW) structure ora multi-quantum well (MQW) structure. In the active layer, electrons andholes are recombined so as to generate and emit light.

Hereinafter, a conventional nitride semiconductor LED will be describedin detail with reference to FIG. 1.

FIG. 1 is a sectional view illustrating the structure of theconventional nitride semiconductor LED. As shown in FIG. 1, the nitridesemiconductor LED includes an optically-transparent sapphire substrate110, an n-type nitride semiconductor layer 120, an active layer 140containing InGaN with a single quantum well (SQW) structure or amulti-quantum well (MQW) structure, and a p-type nitride semiconductorlayer 150, which are sequentially laminated on the sapphire substrate110.

Portions of the p-type nitride semiconductor layer 150 and the activelayer 140 are removed by mesa-etching such that a portion of the uppersurface of the n-type nitride semiconductor layer 120 is exposed.Further, on the exposed upper surface of the exposed n-type nitridesemiconductor layer 120, a negative electrode (n-electrode) is formed.On the surface of the p-type nitride semiconductor layer 150, a positiveelectrode (p-electrode) is formed.

In the multi-quantum well structure having a plurality of mini-bands,the efficiency thereof is excellent, and light emission can be performedby using a small current. Therefore, the multi-quantum well structurehas a larger light-emission output than the single quantum wellstructure, which makes it possible to expect the enhancement of diodecharacteristics.

In such a conventional nitride semiconductor LED, an electron emittinglayer 130 composed of an InGaN/GaN layer is formed between the activelayer 140 and the n-type nitride semiconductor layer 120. The InGaNlayer and the GaN layer increase an effective electron number, which issmaller than an effective hole number, by using a tunneling effect,thereby effectively serving as the electron emitting layer 130 whichincreases a probability of capturing carriers in the active layer 140.

Such an electron emitting layer 130 increases a lattice period through aplurality of slim InGaN/GaN layers. Therefore, the electron emittinglayer 130 reduces a driving voltage and increases light-emissionefficiency, thereby having a good effect on ESD characteristics.

However, when the InGaN layer is grown, it is difficult to adjust gaspressure, because equilibrium vapor pressure of In is extremely high andequilibrium vapor pressure of NH₄ serving as a source gas of N is low.Further, in order to obtain an InGaN layer having excellentcrystallinity, the InGaN layer should be grown at high temperature ofmore than 1000° C. In such a temperature condition, however, most of Inis vaporized, which makes it difficult to produce InN. Further, when thetemperature is decreased, the quality of InGaN is severely degraded.Therefore, it is very difficult to produce an InGaN layer with a highquality.

Therefore, in this technical field, a new method is being required, inwhich an electron emitting layer with excellent crystallinity isobtained so that light-emission efficiency and ESD characteristics of anLED can be enhanced.

SUMMARY OF THE INVENTION

An advantage of the present invention is that it provides a nitridesemiconductor LED in which an electron emitting layer having excellentcrystallinity is grown so that light emission efficiency and ESD(electrostatic discharge) characteristic of an LED can be enhanced.

Additional aspect and advantages of the present general inventiveconcept will be set forth in part in the description which follows and,in part, will be obvious from the description, or may be learned bypractice of the general inventive concept.

According to an aspect of the invention, a nitride semiconductor lightemitting diode (LED) comprises an n-type nitride semiconductor layer; anelectron emitting layer formed on the n-type nitride semiconductorlayer, the electron emitting layer being composed of a nitridesemiconductor layer including a transition element of group III; anactive layer formed on the electron emitting layer; and a p-type nitridesemiconductor layer formed on the active layer.

According to another aspect of the invention, the electron emittinglayer is composed of at least one Ga_(x)Sc_((1-x))N/Al_(y)Ga_((1-y))Nlayer (0≦x<1 and 0≦y<1).

According to a further aspect of the invention, the thicknesses of theGa_(x)Sc_((1-x))N layer and the Al_(y)Ga_((1-y))N layer composing theelectron emitting layer are equal to or different from each other.

According to a still further aspect of the invention, when the electronemitting layer is composed of more than twoGa_(x)Sc_((1-x))N/Al_(y)Ga_((1-y))N layers (0≦x<1 and 0≦y<1), thethicknesses of the respective Ga_(x)Sc_((1-x))N layers composing theelectron emitting layer are equal to or different from each other.

According to a still further aspect of the invention, theGa_(x)Sc_((1-x))N layer and the Al_(y)Ga_((1-y))N layer composing theelectron emitting layer are not doped with impurities.

According to a still further aspect of the invention, all or some of theGa_(x)Sc_((1-x))N/Al_(y)Ga_((1-y))N layers (0≦x<1 and 0≦y<1) composingthe electron emitting layer are doped with n-type impurities.

According to a still further aspect of the invention, theGa_(x)Sc_((1-X))N layer and the Al_(y)Ga_((1-y))N layer composing theelectron emitting layer are doped with the n-type impurities in the sameconcentration or different concentration.

According to a still further aspect of the invention, the electronemitting layer is composed of at least oneGa_(x)Y_((1-X))N/Al_(y)Ga_((1-y))N layer (0≦x<1 and 0≦y<1).

According to a still further aspect of the invention, the nitridesemiconductor LED further comprises another electron emitting layerformed between the active layer and the p-type nitride semiconductorlayer, the electron emitting layer being composed of a nitridesemiconductor layer including a transition element of group Ill.

According to a still further aspect of the invention, a nitridesemiconductor LED comprises an n-type nitride semiconductor layer; anactive layer formed on the n-type nitride semiconductor layer; anelectron emitting layer formed on the active layer, the electronemitting layer being composed of a nitride semiconductor layer includinga transition element of group III; and a p-type nitride semiconductorlayer formed on the electron emitting layer.

According to a still further aspect of the invention, a nitridesemiconductor LED comprises a substrate; an n-type nitride semiconductorlayer formed on the substrate; an electron emitting layer formed on aportion of the n-type nitride semiconductor layer, the electron emittinglayer being composed of a nitride semiconductor layer including atransition element of group III; an active layer formed on the electronemitting layer; a p-type nitride semiconductor layer formed on theactive layer; a p-electrode formed on the p-type nitride semiconductorlayer; and an n-electrode formed on the n-type nitride semiconductorlayer where the electron emitting layer is not formed.

According to a still further aspect of the invention, a nitridesemiconductor LED comprises a substrate; an n-type nitride semiconductorlayer formed on the substrate; an active layer formed on a portion ofthe n-type nitride semiconductor layer; an electron emitting layerformed on the active layer, the electron emitting layer being composedof a nitride semiconductor layer including a transition element of groupIII; a p-type nitride semiconductor layer formed on the electronemitting layer; a p-electrode formed on the p-type nitride semiconductorlayer; and an n-electrode formed on the n-type nitride semiconductorlayer where the active layer is not formed.

According to a still further aspect of the invention, a nitridesemiconductor LED comprises a p-electrode; a p-type nitridesemiconductor layer formed on the p-electrode; an active layer formed onthe p-type nitride semiconductor layer; an electron emitting layerformed on the active layer, the electron emitting layer being composedof a nitride semiconductor layer including a transition element of group111; an n-type nitride semiconductor layer formed on the electronemitting layer; a substrate formed on the n-type nitride semiconductorlayer; and an n-electrode formed on the substrate.

According to a still further aspect of the invention, a nitridesemiconductor LED comprises a p-electrode; a p-type nitridesemiconductor layer formed on the p-electrode; an electron emittinglayer formed on the p-type nitride semiconductor layer, the electronemitting layer being composed of a nitride semiconductor layer includinga transition element of group III; an active layer formed on theelectron emitting layer; an n-type nitride semiconductor layer formed onthe active layer; a substrate formed on the n-type nitride semiconductorlayer; and an n-electrode formed on the substrate.

According to a still further aspect of the invention, the substrate isany one selected from the group consisting of a GaN substrate, an SiCsubstrate, a ZnO substrate, and a conductive substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the present generalinventive concept will become apparent and more readily appreciated fromthe following description of the embodiments, taken in conjunction withthe accompanying drawings of which:

FIG. 1 is a sectional view illustrating the structure of a conventionalnitride semiconductor LED;

FIGS. 2 to 4 are sectional views illustrating the structure of a nitridesemiconductor LED according to a first embodiment of the invention;

FIG. 5 is a graph showing bandgap energy of AIN and GaN; and

FIGS. 6 to 8 are sectional views illustrating the structure of a nitridesemiconductor LED according to a second embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the embodiments of the presentgeneral inventive concept, examples of which are illustrated in theaccompanying drawings, wherein like reference numerals refer to likeelements throughout. The embodiments are described below in order toexplain the present general inventive concept by referring to thefigures.

Hereinafter, embodiments of the present invention will be described indetail with reference to the accompanying drawings.

FIRST EMBODIMENT

Referring to FIGS. 2 to 5, a nitride semiconductor LED according to afirst embodiment of the invention will be described in detail.

FIGS. 2 to 4 are sectional views illustrating the structure of thenitride semiconductor LED according to the first embodiment of theinvention, showing an example of a lateral nitride semiconductor LED.

As shown in FIG. 2, the nitride semiconductor LED according to the firstembodiment includes a substrate 210, an n-type nitride semiconductorlayer 220, an electron emitting layer 230, an active layer 240, and ap-type nitride semiconductor layer 250, which are sequentially formed onthe substrate 210.

Preferably, the substrate 210 is formed of a transparent materialincluding sapphire. In addition to sapphire, the substrate 210 may beformed of zinc oxide (ZnO), gallium nitride (GaN), silicon carbide(SiC), or aluminum nitride (AIN).

Between the substrate 210 and the n-type nitride semiconductor layer220, a buffer layer (not shown) for enhancing lattice matchingtherebetween may be formed. The buffer layer may be formed of GaN orAIN/GaN.

The n-type and p-type nitride semiconductor layers 220 and 250 and theactive layer 240 can be formed of a semiconductor material having acompositional formula of Al_(y)In_(x)Ga_((1-X-y))N (here, 0≦x, 0<y, andx+y≦1). More specifically, the n-type nitride semiconductor layer 220can be formed of a GaN or GaN/AlGaN layer doped with n-type conductiveimpurities. For example, the n-type conductive impurities may be Si, Ge,Sn and the like, among which Si is preferably used. Further, the p-typenitride semiconductor layer 250 can be formed of a GaN or GaN/AlGaNlayer doped with p-type conductive impurities. For example, the p-typeconductive impurities may be Mg, Zn, Be and the like, among which Mg ispreferably used. The active layer 240 can be formed of an InGaN/GaNlayer with a multi-quantum well structure.

Portions of the p-type nitride semiconductor layer 250, the active layer240, and the electron emitting layer 230 are removed by mesa-etchingsuch that a portion of the n-type nitride semiconductor layer 220 isexposed. That is, the p-type nitride semiconductor layer 250, the activelayer 240, and the electron emitting layer 230 are formed on a portionof the n-type nitride semiconductor layer 220.

On the p-type nitride semiconductor layer 250, a p-electrode 260 isformed.

On the n-type nitride semiconductor layer 220 exposed by mesa-etching,an n-electrode 270 is formed.

In such a nitride semiconductor LED according to the invention, theelectron emitting layer 230 is formed between the n-type nitridesemiconductor layer 220 and the active layer 240.

Particularly, the electron emitting layer 230 may be formed of a nitridesemiconductor layer including a transition element of group Ill.

As for the transition element of group III, Sc (scandium) or the likeforming a compound with N (nitride) can be used. The nitridesemiconductor layer including Sc may have a super lattice structurecomposed of at least one Ga_(x)Sc_((1-X))N/Al_(y)Ga_((1-y))N layer(0≦x<1 and 0≦y<1). That is, the electron emitting layer 230 can becomposed of one Ga_(x)Sc_((1-x))N/Al_(y)Ga_((1-y))N layer (0≦x<1 and0≦y<1) or can be formed by laminating more than twoGa_(x)Sc_((1-x))N/Al_(y)Ga_((1-y))N layers (0≦x<1 and 0≦y<1).

Such an electron emitting layer 230 increases a lattice period and formsa mini-band through the plurality of slimGa_(x)Sc_((1-x))N/Al_(y)Ga_((1-y))N layers (0≦x<1 and 0≦y<1). Therefore,the electron emitting layer 230 reduces a driving voltage and increaseslight emission efficiency, thereby having a good effect on ESDcharacteristics.

In other words, the electron emitting layer 230 secures a high carriermobility due to a bandgap difference between Ga_(x)Sc_((1-x))N layer andAl_(y)Ga_((1-y))N layer, thereby enhancing a current spreading effect.When a current spreading effect is enhanced, a driving voltage of an LEDis reduced and light emission efficiency increases so that the magnitudeof ESD protection voltage increases.

When the electron emitting layer 230 is formed by laminating more thantwo Ga_(x)Sc_((1-x))N/Al_(y)Ga_((1-y))N layers (0≦x<1 and 0≦y<1),compositional ratios of Ga and Sc within Ga_(x)Sc_((1-x))N forming therespective layers may differ from each other, and compositional ratiosof Al and Ga within Al_(y)Ga_((1-y))N forming the respective layers maydiffer from each other. Further, when the electron emitting layer 230 isformed by laminating more than two Ga_(x)Sc_((1-x))N/Al_(y)Ga_((1-y))Nlayers (0≦x<1 and 0≦y<1) as described above, the thicknesses of therespective Ga_(x)Sc_((1-x))N layers composing the electron emittinglayer 230 may be equal to or different from each other.

Further, in the Ga_(x)Sc_((1-x))N/Al_(y)Ga_((1-y))N layer (0≦x<1 and0≦y<1) composing the electron emitting layer 230, the thicknesses of theGa_(x)Sc_((1-x))N layer and the Al_(y)Ga_((1-y))N layer may be equal toor different from each other. At this time, considering a tunnelingeffect in the electron emitting layer 230, it is preferable that thethickness of the Ga_(x)Sc_((1-x))N/Al_(y)Ga_((1-y))N layer (0≦x<1 and0≦y<1) is set to be equal to or less than 100 Å. More preferably, thethickness is set to be equal to or less than 70 Å or 50 Å.

Preferably, all or some of the Ga_(x)Sc_((1-x))N/Al_(y)Ga_((1-y))Nlayers composing the electron emitting layer 230 are doped with n-typeimpurities. However, the Ga_(x)Sc_((1-X))N layer and theAl_(y)Ga_((1-y))N layer may not be doped with impurities.

When the Ga_(x)Sc_((1-x))N/Al_(y)Ga_((1-y))N layer is doped with n-typeimpurities, the doping concentration of n-type impurities is preferablyequal to or less than 5×10²¹/cm³, in consideration of the outputreduction of an LED. More preferably, the doping concentration of n-typeimpurities is equal to or less than 1×10²¹/cm³. As for the n-typeimpurities, Si, Ge, Sn and the like are used. Preferably, Si or Sn isused.

The Ga_(x)Sc_((1-x))N layer and the Al_(y)Ga_((1-y))N layer composingthe electron emitting layer 230 may be doped with the n-type impuritiesin the same concentration or in different concentration.

As such, the electron emitting layer 230 can be obtained by growing aGa_(x)Sc_((1-x))N/Al_(y)Ga_((1-y))N layer (0≦x<1 and 0≦y<1) which is anitride semiconductor layer including a transition element of group III,such as Sc.

In the related art, the InGaN layer of the electron emitting layercomposed of an InGaN/GaN layer cannot be grown at high temperature ofmore than 1000° C. because of a low binding force of InN. Therefore, itis difficult to secure excellent crystallinity. In the presentinvention, however, the electron emitting layer 230 is composed of aGa_(x)Sc_((1-x))N layer including Sc which can be grown at hightemperature of more than 1000° C. because it has a high melting pointand a high binding force, instead of InGaN. Therefore, it is possible tosecure more excellent crystallinity than an existing electron emittinglayer composed of InGaN/GaN layer.

As for the transition element of group III to be included in theelectron emitting layer 230, Y (yttrium) may be used instead of Sc. Thatis, the electron emitting layer 230 may be composed of aGa_(x)Y_((1-x))N/Al_(y)Ga_((1-y))N layer (0≦x<1 and 0≦y<1) instead of aGa_(x)Sc_((1-x))N/Al_(y)Ga_((1-y))N layer (0≦x<1 and 0≦y<1).

Since Y (yttrium) of the Ga_(x)Y_((1-x))N layer also has a high meltingpoint and a high binding force, the Ga_(x)Y_((1-x))N layer can be grownat high temperature of more than 1000° C. Therefore, it is possible tosecure more excellent crystallinity than an existing electron emittinglayer composed of InGaN/GaN layer.

Meanwhile, the above-described electron emitting layer 230 of thenitride semiconductor LED according to the invention may not formedbetween the n-type nitride semiconductor layer 220 and the active layer240, but may be formed between the active layer 240 and the p-typenitride semiconductor layer 250, as shown in FIG. 3. Further, theelectron emitting layer 230 may be formed between the n-type nitridesemiconductor layer 220 and the active layer 240 and between the activelayer 240 and the p-type nitride semiconductor layer 250, as shown inFIG. 4. In FIG. 4, reference numerals 230 a and 230 b represent firstand second electron emitting layers, respectively.

As such, the electron emitting layer 230 composed of at least oneGa_(x)Y_((1-x))N/Al_(y)Ga_((1-y))N layer (0≦x<1 and 0≦y<1) orGa_(x)Sc_((1-x))N/Al_(y)Ga_((1-y))N layer (0≦x<1 and 0≦y<1), which canbe grown at high temperature so as to secure excellent crystallinity, isgrown in the vicinity of the active layer 240, thereby enhancing lightemission efficiency and ESD characteristics of an LED.

The electron emitting layer 230 includes an Al_(y)Ga_((1-y))N layerwhich can be grown by using AIN and GaN.

FIG. 5 is a graph showing bandgap energy of AIN and GaN.

According to the invention, Al is inserted into the Al_(y)Ga_((1-y))Nlayer such that bandgap can be adjusted in various manners within athick solid line shown in FIG. 5. That is, a bandgap difference from theGa_(x)Sc_((1-x))N layer is further increased by inserting Al. Then,electron confinement is strengthened and a difference in currentdistribution is provided, so that the nitride semiconductor LED can beprotected from a sudden surge voltage or static electricity. Therefore,it is possible to enhance ESD characteristics of an LED.

SECOND EMBODIMENT

Hereinafter, a nitride semiconductor LED according to a secondembodiment of the invention will be described in detail with referenceto FIGS. 6 to 8.

FIGS. 6 to 8 are sectional views illustrating the structure of thenitride semiconductor LED according to the second embodiment of theinvention, showing an example of a vertical nitride semiconductor LED.

As shown in FIG. 6, the nitride semiconductor LED has a p-electrode 260formed in the lowermost portion thereof. Preferably, the p-electrode 260is formed of metal with high reflectance so as to serve as an electrodeand a reflecting layer.

On the p-electrode 260, a p-type nitride semiconductor layer 250, anactive layer 240, an electron emitting layer 230, an n-type nitridesemiconductor layer 220, and a substrate 200 are sequentially formed. Onthe substrate 200, an n-electrode 270 is formed.

The substrate 200 serves to induce spreading of carriers so as to reduceresistance. The substrate 200 may be formed of any one selected from thegroup consisting of a GaN substrate, an SiC substrate, a ZnO substrate,and a conductive substrate.

As described above, the p-type nitride semiconductor layer 250 may beformed of a GaN or GaN/AlGaN layer doped with p-type conductiveimpurities, the active layer 240 may be formed of an InGaN/GaN layerwith a multi-quantum well (MQW) structure, and the n-type nitridesemiconductor layer 220 may be formed of a GaN or GaN/AlGaN layer dopedwith n-type conductive impurities.

As described above, the electron emitting layer 230, which serves toreduce a driving voltage of an LED and to enhance light emissionefficiency and ESD characteristics, may be formed of a nitridesemiconductor layer including a transition element of group Ill.

As for the transition element of group III, Sc (scandium) or the likemay be used. The nitride semiconductor layer including Sc may be formedof at least one Ga_(x)Sc_((1-X))N/Al_(y)Ga_((1-y))N layer (0≦x<1 and0≦y<1).

The electron emitting layer 230 secures a high carrier mobility due to abandgap difference between Ga_(x)Sc_((1-x))N layer and Al_(y)Ga_((1-y))Nlayer, thereby enhancing a current spreading effect. When a currentspreading effect is enhanced, a driving voltage of an LED is reduced andlight emission efficiency thereof increases so that the magnitude of ESDprotection voltage increases.

When the electron emitting layer 230 is formed by laminating more thantwo Ga_(x)Sc_((1-x))N/Al_(y)Ga_((1-y))N layers (0≦x<1 and 0≦y<1),compositional ratios of Ga and Sc within Ga_(x)Sc_((1-x))N forming therespective layers may differ from each other, and compositional ratiosof Al and Ga within Al_(y)Ga_((1-y))N forming the respective layers maydiffer from each other. Further, when the electron emitting layer 230 isformed by laminating more than two Ga_(x)Sc_((1-x))N/Al_(y)Ga_((1-y))Nlayers (0≦x<1 and 0≦y<1) as described above, the thicknesses of therespective Ga_(x)Sc_((1-x))N layers composing the electron emittinglayer 230 may be equal to or different from each other.

Further, the thicknesses of the Ga_(x)Sc_((1-x))N layer and theAl_(y)Ga_((1-y))N layer composing the electron emitting layer 230 may beequal to or different from each other.

Preferably, all or some of the Ga_(x)Sc_((1-x))N/Al_(y)Ga_((1-y))Nlayers composing the electron emitting layer 230 are doped with n-typeimpurities. The Ga_(x)Sc_((1-x))N layer and the Al_(y)Ga_((1-y))N layermay be doped with the n-type impurities in the same concentration or indifferent concentration. However, the Ga_(x)Sc_((1-x))N layer and theAl_(y)Ga_((1-y))N layer may not be doped with impurities.

The electron emitting layer 230 is composed of a Ga_(x)Sc_((1-x))N layerincluding Sc which can be grown at high temperature of more than 1000°C. because it has a high melting point and a high binding force.Therefore, it is possible to secure more excellent crystallinity than inan existing electron emitting layer composed of an InGaN/GaN layer.

As for the transition element of group III to be included in theelectron emitting layer 230, Y (yttrium) may be used instead of Sc. Anitride semiconductor layer including Y (yttrium) may be composed of atleast one Ga_(x)Y_((1-x))N/Al_(y)Ga_((1-y))N layer (0≦x<1 and 0≦y<1).Since Y (yttrium) of the Ga_(x)Y_((1-x))N layer also has a high meltingpoint and a high binding force, the Ga_(x)Y_((1-x))N layer can be grownat high temperature of more than 1000° C. Therefore, it is possible tosecure more excellent crystallinity than in an existing electronemitting layer composed of an InGaN/GaN layer.

Further, the above-described electron emitting layer 230 of the nitridesemiconductor LED according to the invention may not formed between then-type nitride semiconductor layer 220 and the active layer 240, but maybe formed between the p-type nitride semiconductor layer 250 and theactive layer 240, as shown in FIG. 7. Further, the electron emittinglayer 230 may be formed between the p-type nitride semiconductor layer250 and the active layer 240 and between the active layer 240 and then-type nitride semiconductor layer 220, as shown in FIG. 8. In FIG. 8,reference numerals 230 a and 230 b represent first and second electronemitting layers, respectively.

In the second embodiment, the electron emitting layer 230 composed of atleast one Ga_(x)Sc_((1-x))N/Al_(y)Ga_((1-y))N layer (0≦x<1 and 0≦y<1) orGa_(x)Y_((1-x))N/Al_(y)Ga_((1-y))N layer (0≦x<1 and 0≦y<1), which can begrown at high temperature so as to secure excellent crystallinity, isgrown in the vicinity of the active layer 240, thereby obtaining thesame operation and effect as the second embodiment.

According to the nitride semiconductor LED of the invention, theelectron emitting layer is formed of aGa_(x)Sc_((1-x))N/Al_(y)Ga_((1-y))N layer (0≦x<1 and 0≦y<1) orGa_(x)Y_((1-x))N/Al_(y)Ga_((1-y))N layer (0≦x<1 and 0≦y<1), which can begrown at high temperature so as to secure more excellent crystallinitythan an existing InGaN/GaN layer. Therefore, it is possible to enhancelight emission efficiency and ESD characteristics of an LED.

Although a few embodiments of the present general inventive concept havebeen shown and described, it will be appreciated by those skilled in theart that changes may be made in these embodiments without departing fromthe principles and spirit of the general inventive concept, the scope ofwhich is defined in the appended claims and their equivalents.

1-8. (canceled)
 9. A nitride semiconductor light emitting diode (LED)comprising: an n-type nitride semiconductor layer; a first electronemitting layer formed on the n-type nitride semiconductor layer, theelectron emitting layer being composed of a nitride semiconductor layerincluding a transition element of group III; an active layer formed onthe electron emitting layer; a p-type nitride semiconductor layer formedon the active layer; and a second electron emitting layer formed betweenthe active layer and the p-type nitride semiconductor layer, the secondelectron emitting layer being composed of a nitride semiconductor layerincluding a transition element of group III. 10-18. (canceled)
 19. Anitride semiconductor light emitting diode (LED) comprising: asubstrate; an n-type nitride semiconductor layer formed on thesubstrate; a first electron emitting layer formed on a portion of then-type nitride semiconductor layer, the electron emitting layer beingcomposed of a nitride semiconductor layer including a transition elementof group III; an active layer formed on the electron emitting layer; ap-type nitride semiconductor layer formed on the active layer; ap-electrode formed on the p-type nitride semiconductor layer; ann-electrode formed on the n-type nitride semiconductor layer where theelectron emitting layer is not formed; and a second electron emittinglayer formed between the active layer and the p-type nitridesemiconductor layer, the second electron emitting layer being composedof a nitride semiconductor layer including a transition element of groupIII. 20-29. (canceled)
 30. A nitride semiconductor light emitting diode(LED) comprising: a p-electrode; a p-type nitride semiconductor layerformed on the p-electrode; an active layer formed on the p-type nitridesemiconductor layer; a first electron emitting layer formed on theactive layer, the electron emitting layer being composed of a nitridesemiconductor layer including a transition element of group III; ann-type nitride semiconductor layer formed on the electron emittinglayer; a substrate formed on the n-type nitride semiconductor layer; ann-electrode formed on the substrate; and a second electron emittinglayer formed between the p-type nitride semiconductor layer and theactive layer, the electron emitting layer being composed of a nitridesemiconductor layer including a transition element of group III. 31-32.(canceled)